A Case of Follicular Thyroid Carcinoma in Which Both the Cystic Cervical Lymph Node and Thyroid Tumor Were Diagnosed as Follicular Nodular Disease

The most important differential diagnoses in patients presenting with cystic cervical lymph node metastasis are human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma and papillary thyroid carcinoma. The diagnostic criteria for follicular thyroid carcinoma are histological confirmation of at least one of capsular invasion, vascular invasion, or metastasis outside the thyroid gland, and cell atypia has no role in distinguishing between benign and malignant disease. We report a case of follicular nodular disease in a cervical lymph node that required to be differentiated from cervical lymph node metastasis secondary to papillary or follicular thyroid carcinoma.